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Not getting clear focus on 40mm Summicron

judge

Member
Hi,

I just acquired a 40mm Summicron lens and it seems not to focus dead-on with my M4 P.

At less than a meter, the item/part I focus on comes out blurred in print. Everything behind the item/part I focused on is damn clear.

Using hyperfocal distance focusing results to very clear print. Same when I just use eternity.

Does this mean that my 40mm doesn't focus when I actually use the viewfinder? Or when the object is near a meter distance?

I inquired before in this forum whether 40mm has a focussing problem, but majority of the people who responded and used 40mm seems not to encounter such problem.

Is there a way I can solve this problem, should i just hyperfocus or should I just sell my lens and buy a 50mm or 35mm?

Thanks in advance!

Cheers,

Jury
 
Dear Jury,

The focusing-cam on the C lenses is steeper than those on M lenses. When the CL was introduced Leitz cautioned the use of C lenses on M cameras for this very reason.

My Summicron-C 1:2/40 focuses perfectly on all M cameras, however if I were experiencing your problem I would have the range-finder of the M4P checked for accuracy. They do need periodic adjustment in my experience.

I would be surprised if this did not fix the problem although I would not expect pinsharp accuracy at close distances with the Summicron-C on an M camera.

Best of luck.

Justin
 
> My 40mm Summicron works fine at all distances with both a CL & M4. But I would like to know how you handle the framing problem. Do you guestimate a frame wider than the 50mm frame? Use the lever to call up the 35mm > frame & imagine something in-between 50 & 35? Or do you have some other trick?

> LG
 
Dear Louis,

Firstly I do not use the 40mm lens very often on an M camera, but when I do, the procedure for framing is as you suggested or through an accessory viewfinder in the accessory shoe.

My reason for using it with an M camera was when the light required a faster lens than the Tri-Elmar. The Summicron-C is very compact with its lens-hood rolled back and can be kept in ones pocket in reserve. I have since acquired a pre-aspherical Summilux-M 35mm.

Regards,

Justin
 
Hi Louis,

Last week I made a very primitive test to find out the difference of 50mm framelines to what is actually captured on film by using the living room wall and lots of black tape.

At 2.5 meters, I made a box made of black tape on the wall that covers the 50mm framelines on my camera and took a picture and moved back to 5 meters, made another box that covers 50mm and took another picture.

Comparing the actual print, I find that at 2.5 meters, there is almost an extra foot on each side of my "50mm" black box, and half a foot below and above it.

I flicked the 35mm frameline on my camera and found that if i moved 3 to four inches nearer the wall, the 35mm frameline is exactly covering what the print covered.

If I moved a foot and a half away, the "50mm" framelines in my camera covers what the print covered.

In other words, at 2.5 meters, the 35mm is nearer to what the the film actually covered when printed.

At 5 meters, the 50mm framelines in my camera is way off the actual print but the 35mm framelines in my camera almost covered it.

Regards,

Jury
 
Dear Jury & Justin: thanks for the info. Jury: you don't mention it but I presume you did the tests with the 4omm lens? If so, it indicates that the 35mm frame would be better as a guide to what this lens sees than the 50 mm frame called up by the lens... This is useful information.

Louis

>
 
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